I tried the big ball stretch and my neck, shoulders and arms went numb for two weeks. I guess this really aggravated the scalenes.
So start easy with this one.

Also the door frame pec minor stretch totally does not work for me.
Tried it multiple times over the past year. Pain in scapula, then (if I keep on stretching) numbness in hand then (if I keep on stretching for several days) weakness in arm.
I use pin and stretch technique combined with manual release, seeing some minor improvements in scapular winging, but nothing dramatic.